1. Field of the Invention
The present invention relates to a touch screen, a display device with a touch screen, and a manufacturing method thereof, and more particularly, to a capacitive touch screen, a display device with a touch screen, and a manufacturing method thereof.
2. Description of the Related Art
Display devices having an input unit (hereinafter, referred to as a touch screen) which inputs information through a pressing operation (hereinafter, referred to as touch) using a user s finger or the like have been known. Such display devices are used in mobile electronic apparatuses such as personal digital assistance (PDA) or mobile terminals, various home electric appliances, stationary information terminals such as unmanned reception apparatuses, and the like. Touch screens are classified into a resistive type detecting a variation in resistance of a touched part, a capacitive type detecting a variation in capacitance, and an optical sensor type detecting a variation in a light intensity of a part shielded by a touch.
The capacitive type has a merit that transmittance is higher than that of the resistive type or the optical sensor type. In the resistive type, since the touched position is sensed through mechanical contact with a resistive film, the resistive film is in danger of deteriorating or being damaged (cracked). The capacitive type needs no mechanical contact such as a contact of a detection electrode with another electrode and is thus advantageous in durability.
JP2009-258888 A discloses a capacitive touch screen. Specifically, the touch screen includes vertical X electrodes and horizontal Y electrodes which are arranged in a matrix shape in the vertical and horizontal directions of the touch screen and a Z electrode that covers the plane of the touch screen and that is in an electrically-floating state. By employing this configuration, it is possible to detect coordinates on the basis of variations in capacitance between the X electrodes and the Z electrode and between the Y electrodes and the Z electrode, for example, due to a touch on the touch screen.